Simulating a Constant Pressure Heat Exchanger

I am attempting to simulate a constant pressure (atmospheric) heat exchanger and control system. The system is very simple, containing a single vessel of water, which is open to the atmosphere. Fluid is pumped from the vessel past a heating element and back into the original vessel.

I would like to use the Foundation Library, but the only element which comes close to what I need is the constant volume element, which for obvious reasons, is not capable of simulating my system.

Are there any suggestions on how to handle a closed system such as the one I am attempting to model?

Thanks!

Answer 1

[Yifeng Tang]

Why won't a constant volume chamber work? Is that because the inlet and outlet flow may be different instantaneously and the liquid volume may fluctuate as a result?

If so, consider something like this:

The converter block can be used as a changing volume of liquid. With no external load and environment pressure set to atm, the pressure of the liquid inside is always ~1atm. The mass block can be set with a small value, and so is the damper block. They are for numerical purpose mainly.

[Yifeng Tang]

And of course, using the Tank (TL) block in the Simscape Fluids library would be much more straight forward.

https://www.mathworks.com/help/releases/R2021b/physmod/hydro/ref/tanktl.html